Tulip Siddiq, a British Bangladeshi Labour Party lawmaker and a minister, is being investigated by the UK parliament's standards watchdog over a failure to register rental income on a London property.

The Labour MP for Hampstead and Highgate in north London and the economic secretary to the treasury, is being investigated for late registration of interests, reports BBC and the Daily Mail citing the Parliamentary Standards Commissioner's website.

Tulip is the first MP of the new parliament to be placed under investigation by the Standards Commissioner, according to a Daily Mail report.

She previously apologised after breaking MP rules over her financial interests earlier this month, the report said.

A Labour Party spokesperson said, "This was an administrative oversight which was declared with the Commons registrar and Tulip apologised as soon as she was made aware of the issue."

"Tulip will cooperate fully with the Parliamentary Commissioner on Standards on this matter," the spokesperson added.

UK Prime Minister Keir Starmer has repeatedly vowed to beef up integrity in public life. He said this month, "People falling short of the required standards will face consequences, as you would expect."