A disciplinary tribunal fined Gary Senior, 58, formerly senior partner in Europe and the Middle East at the firm, £55,000 for professional misconduct and ordered him to pay £40,000 in costs.

He was found to have harassed the solicitor in a hotel room following a work social event eight years ago.

The panel also found that he was guilty of attempting to interfere with an internal investigation into what had happened.

In a statement following the ruling from the Solicitors Disciplinary Tribunal, Mr Senior said that he “bitterly” regretted the incident.

“The matter was not covered up by the firm,” Mr Senior said. “An investigation was carried out by the firm involving a number of senior partners. At the time I believed I behaved appropriately in that investigation while co-operating with them.”