Campaigners and politicians have criticised the oil company for being slow to release information on the spill A relief valve close to the faulty pipeline at Shell’s Gannet Alpha oil platform in the North Sea appears to be the source of a secondary leak that is adding to the worst oil spill in UK waters in a decade . Green campaigners and members of the Scottish parliament have rounded on the oil company for being slow to release full information on the leak, which was first detected last Wednesday but only disclosed to the public on Friday evening. Shell said on Tuesday that while the leaking well was “under control”, and the main spill had been shut off successfully, a small quantity of oil was still finding its way to the sea by another pathway. After lengthy searching, the valve was pinpointed as the likely source. Work will continue to dam the small quantities of oil – at up to five barrels a day, a trickle compared with the 1,300 barrels thought to have gushed out in the first days of the leak, but Shell could not say how soon it would be completed. The company has also been so far unable to explain how the leak occurred in the first place. Green campaigners accused the company of complacency and secrecy, as information on the progress of the leak continued to be slowly released. Per Fischer, communications officer at Friends of the Earth Scotland, said: “It beggars belief that we are still being drip-fed information and that Shell’s initially ‘insignificant’ leak is still causing problems.” Tony King, head of policy at the Scottish Wildlife Trust, added: “It seems clear that there has been a substantial oil spill in the North Sea, putting sea birds, whales and dolphins, fish and other wildlife at risk. Shell needs to come clean on exactly how much oil has entered the sea. This is an extremely serious matter and wildlife organisations need information in order to plan what, if anything, can be done to safeguard Scotland’s marine wildlife. Once the immediate threat to the environment has been removed, Shell must be open about exactly how this spill came about and what measures it is taking to make sure that it never happens again.” Shell rebuffed these criticisms, saying it had responded “promptly” and “properly”. The company said it had followed correct procedures in alerting the Department of Energy and Climate Change (Decc) first about the leak last week, and agreeing a course of action to stop it. Most of the oil has now been dispersed by the waves, leaving only a small area where a sheen can be seen on the sea surface. Government advisers also played down the risk to bird life, as the oil is unlikely to reach shore from the rig – 112 miles east of Aberdeen – and said the risk to fish was also small as most of the oil should be cleared by natural processes. Officials said that while the leak was the biggest in UK waters for a decade, it was less serious when viewed in context of other major spills such as BP’s blowout in the Gulf of Mexico last year, which was estimated to be spilling up to 70,000 barrels a day . Sarah Boyack, Labour’s environment spokesperson in the Scottish parliament, said people needed more assurances from the government agencies involved: “I want to know from Marine Scotland what contingency plans they put in place to deal with major oil spillages. I also want information on the lessons they learned from the Deepwater Horizon disaster in relation to wildlife protection, protection of public health and protection of the fishing industry.” Glen Cayley, the technical director of Shell UK, said that since the original leak had been shut off last Thursday, the company had been “working to find the source of the much smaller flow of hydrocarbons. It had proved difficult to find because we are dealing with a complex subsea infrastructure and the position of the small leak is in an awkward place surrounded by marine growth. So, it has taken our [remotely operated vehicle] inspections some time to establish exactly where the source is. Once we’ve confirmed this we will then develop a series of mitigation options to stop this leak. There is no new leak.” Green campaigners said the incident raised questions over the safety of oil companies’ plans to drill in deep water in the Arctic , as the North Sea is generally supposed to be the safest in the world in terms of spills. Vicky Wyatt, senior oil campaigner at Greenpeace, said: “As Shell finalises plans to move into the fragile Arctic, where oil spills are almost impossible to clean up, the company has important questions to answer. Meanwhile the government should halt its rush to hand out new licences for deep water drilling to the west of Shetland.” Greenpeace is taking legal action to stop the granting of more than 20 new licences for oil companies to drill in the deep water to the west of Shetland, arguing that the government cannot be certain that a spill in the area would not devastate specially protected wildlife havens. Campaigners also pointed to wider lessons for oil companies in other parts of the world, including places where oil spills have been covered up such as Nigeria. As the Guardian recently revealed , Shell has been forced to admit liability for spills in the region that have dwarfed last year’s Gulf of Mexico disaster. Fischer said: “It is ironic that the information [Shell has] made available is actually vastly better than what was offered to the people of Nigeria, where Shell for a long time denied any responsibility for endless oil spills. For decades, oil companies have acted with impunity when it comes to the environment. At a time when we could be using the skills learnt through oil exploitation to advance our renewable energy resources, we should be placing much higher standards of operation on companies like Shell.” Shell said: “The high winds and waves over the weekend have led to a substantial reduction in the size of the oil sheen as can be seen from the current levels on the water,” said Cayley. “This is a significant spill in the context of annual amounts of oil spilled in the North Sea. We care about the environment and we regret that the spill happened. We have taken it very seriously and responded promptly to it.” Decc said: “Shell has informed us that the oil leak at its pipeline at the Gannet Alpha platform east of Aberdeen is under control and has now been greatly reduced. They are working to completely halt any further leakage. Although small in comparison to the Macondo incident [at one of BP's platforms in the Gulf of Mexico last year], in the context of the UK’s continental shelf the spill is substantial – but it is not anticipated that oil will reach the shore and it is expected that it will be dispersed naturally.” Oil spills Oil Oil and gas companies Energy industry Oil Energy Fossil fuels Royal Dutch Shell Marine life Wildlife Oceans Scotland Fiona Harvey Severin Carrell guardian.co.uk