Oil giant BP has tightened rules on workplace relationships after its former boss was dismissed for failing to disclose details about his personal relationships with colleagues.

Senior managers must now report any intimate relationships that have taken place with colleagues in the last three years.

Any employees who fail to adhere to the new rules may face disciplinary action.

BP said the update to its conflict of interest policy was scheduled for review this year.

About 4,500 staff at managerial level have been asked to submit any reports in the next three months “whether or not they feel they represent a conflict of interest”, the firm said.

It comes after its former chief executive Bernard Looney was found to have committed “serious misconduct” in failing to disclose workplace relationships.

In December, he was dismissed without notice and had to forfeit millions of pounds in share allowances and bonuses.

The firm said that Mr Looney had given “inaccurate and incomplete assurances” as part of an investigation into the relationships in 2022.

Mr Looney said in a statement in December 2023 that he was “disappointed with the way this situation has been handled”.

BP first launched a review of Mr Looney’s relationships with colleagues in 2022 following an anonymous tip-off.

At the time, the company said Mr Looney disclosed “a small number of historical relationships with colleagues prior to becoming [chief executive]” and it found no breach of company conduct.

Mr Looney gave assurances then about disclosing the past relationships, as well as his future behaviour.

The board later said it had, however, received similar allegations, prompting another review.

On Monday, the company said that it had updated its conflict of interest policy after looking at comparable organisations and good industry practice.

Previously, employees were only required to disclose and record family or intimate relationships at work if they felt there could be a conflict of interest.

The new policy came into effect at the beginning of June and the changes reflect “the influence that leaders have”, BP added.

Rachel Suff, wellbeing and employee relations adviser at the Chartered Institute of Personnel and Development (CIPD), said that formal policies on relationships are more common in the US than in the UK.

Many employers will take a “common-sense approach”, but she said that any relationships between managers and employees would be a clear conflict of interest and should be reported as they could create risks around confidentiality and fairness.

Mr Looney had spent his career at BP, which he joined in 1991 as a drilling engineer.

Born in Ireland and raised on a farm, he became a member of its executive team in 2010.

He had presented himself as more approachable, posting pictures of smiling employees on Instagram when he took over as chief executive in 2020.

However, he faced scrutiny for watering down targets on cutting net carbon emissions.

His departure from BP also came at a time when executives at high-profile organisations such as the CBI faced questions over their personal behaviour.

For senior managers in particular, “it’s vital that their behaviour is respectful and professional at all times”, Ms Suff added.