The 3,900–dwt tanker Asphalt Venture (built 1991) was seized in the Somali basin on 28 September, 2010, with a crew of 15. In April 2011, the vessel and eight men were freed.

The Maritime Piracy Humanitarian Response Programme (MPHRP) said on Thursday: “Following lengthy negotiations, the release of these men was arranged after a modest payment was made to cover the logistical and transport costs of the group holding the men.”

Preparations are being made for their return to India in the next few days and their families have been informed, it added.

MPHRP chairman Peter Swift said: “After more than four years in captivity we are delighted for them and their families after the terrible ordeal and hardship that they have suffered.

“The tremendous efforts and generous support of all those who helped to secure their release and safe return are greatly appreciated, including the team at Holman Fenwick Willan, who stepped in on a pro bono basis to help make this happen.”

However, the organisation said 30 seafarers and fishermen are still being held in Somalia.

It believes the gunmen think they can raise substantial money from ransom payments, whereas it is charities working to free them.