The Financial Conduct Authority (FCA) said former chief executive Richard Howson and former finance directors Richard Adam and Zafar Khan were to pay £397,800, £318,000 and £154,400 respectively.

The penalties were related to three "misleadingly positive statements about Carillion's financial performance generally and in relation to its UK construction business in particular" from December 2016 to May 2017, the FCA said.

The company's demise in January 2018 was the country's biggest bankruptcy for a decade.

The outsourcer employed 43,000 people across the defence, education, health, transport, and construction sectors in its prime.

The FCA said it would have fined Carillion £37.8m had it not gone bust - also sparking investigations by MPs and the Financial Reporting Council (FRC).

The latter ruled earlier this week that accountancy firm KPMG would pay £18.35m over its handling of audit work at Carillion.

The FRC highlighted potentially conniving behaviour among some of its former staff when they reported to regulators.

It stripped four former KPMG staff of their memberships of the Institute of Chartered Accountants for between seven and 10 years.

The FRC itself has also been the subject of a review, with many proposed reforms to improve oversight standards yet to be introduced.

The FCA said of its findings: "The FCA... considers that Mr Howson, Mr Adam and Mr Khan acted recklessly and were knowingly concerned in Carillion's contraventions.

"Despite their awareness of these deteriorations and increasing risks, they also failed to make the board and the audit committee aware of them, resulting in a lack of proper oversight."

The three men are appealing against the decision in the Upper Tribunal court, the FCA said.

They were yet to release statements in response to the FCA's findings.