The company said the lump sum of £1,057, 971 was based on the amount he could expect to receive if he had stayed in the job until his normal retirement date in June next year.

Watts will also receive a £584,070 annual pension.

An internal audit committee reported that 4.85 billion barrels would be downgraded from its reserves estimates, an increase on the last figure of 4.14 billion barrels, which was an increase again on the original downgraded estimates – 3.9 billion barrels.

Watts was removed as chairman in March this year.