HANOI (Reuters) - Vietnam’s ruling Communist Party on Sunday dismissed a high-profile party official from his politburo position for misconduct while he headed the country’s state oil and gas firm.

The vote to remove Dinh La Thang, 56, one of the 19 members of the country’s most powerful politburo, was a rare sanction for such a prominent official in the one-party state.

In an online statement, the party said that while he was chairman of PetroVietnam between 2009-2011, Thang had committed “weaknesses and serious violations in his leadership, command and staff works...sparking annoyance among officials, party members and the people.”

On April 27, the party’s inspection committee said Thang had been responsible numerous illegal projects and big financial losses of PetroVietnam, and overseen the company’s acquisition of an excessive stake in Ocean Bank of Ocean Group. The bank’s founder and ex-chairman was arrested in 2014.

Thang’s dismissal comes amid a wider crackdown on corrupt officials at PetroVietnam and its subsidiaries, including Drilling Mud Corp.

Another former PetroVietnam chairman was detained in 2015 and three other senior officials at the company face possible sanctions for related offences.

In its statement, the party made no mention of whether Thang would retain his post as party chief of Vietnam’s economic hub Ho Chi Minh City.

Thang was an unusually outspoken official among normally-reticent Communist Party apparatchiks, known for his forthright comments on sensitive issues. He once phoned a top executive at dairy firm Vinamilk’s and asked the company to help cow farmers.

Thang headed several state firms and was the minister of transport before he secured a politburo position in 2016.

It is unusual in Vietnam for a senior official to be dismissed while still holding a position.

It is unclear whether another party member will be appointed to replace Thang.