In a potential setback to investigations on Mumbai attacks, a woman who had witnessed six terrorists land in the city has gone missing.

Police said on Tuesday that Anita Uddaiya, who saw six people leaving an airboat at the Fisherman's Colony in Cuffe Parade on November 26, has been missing since January 11.

Mumbai police had recently taken her to a hospital to identify bodies of the six terrorists.

Police said they have launched a search for the missing witness after her daughter filed a missing persons report.

"We are also probing the disappearance of the lady since she is a witness in the case," Joint Commissioner of Police (Crime) Rakesh Maria said.

However, he said, Uddaiya is not considered as a key witness in the case of arrested terrorist Mohammed Ajmal Amir Kasab.

Britain's intelligence service MI5 chief said earlier this week that his agency has uncovered links between the Mumbai attackers and the UK nationals.

"We have looked at individuals' communications, where they have been and so on and found they have got connections with most countries including the UK, but not of national security significance," said MI5 Director General Jonathan Evans.

MVZ/JG/DT