Tullow Oil sues Heritage over unpaid Ugandan tax bill

Tullow filed its claim at London's High Court, having been left in a difficult position after it bought out Heritage's 50pc stake last June for $1.45bn.

Heritage then disputed a $434m tax bill hanging over the transaction, of which $313m was not paid to the Ugandan government.

The authorities stopped Tullow from working on the field and proceeding with the onward sale of stakes to CNOOC and Total until Tullow handed over $313m in "security" for the unpaid bill.

Heritage is still in dispute with the Ugandan government and the lawsuit is Tullow's attempt to "shift the liability back where it belongs".

It claims in the suit that the contract governing the sale of the Lake Albert assets means Heritage has to reimburse it.

A spokesman said: "This is an entirely separate action from the tax related procedures and doesn't prejudge the outcome of any other actions. Tullow is claiming its contractual rights of reimbursement following the payment of a security to the Ugandan government. It is the company's clear duty to its shareholders to reclaim that money."

Heritage said the claim is "misguided" because Tullow's payment to Uganda "was made without [its] knowledge or consent" and "the sale is not taxable under Ugandan law". It is "continuing to review [its] options to recover approximately $121m held on deposit with Government".

Tullow, Total and CNOOC are now proceeding with their massive $10bn development of the Lake Albert fields, plus a new refinery and pipeline to the east coast of Africa. The argument over tax has caused the project to run behind schedule already.