The Inland Revenue Board (IRB) appears to be targeting companies owned by all three of Dr Mahathir Mohamad's sons.

Contacted today, a senior executive at Crescent Capital Sdn Bhd, a venture capital firm founded and headed by Mirzan Mahathir, confirmed that the IRB raided the office on Tuesday.

"We were raided by eight to 10 IRB officers and some files were taken away," said the spokesperson, who declined to be named.

A spokesperson of Opcom Holdings Bhd, a fibre-optics company founded by Mukhriz Mahathir and headed by his elder brother Mokhzani, confirmed the company was raided on the same day.

However, the spokesperson declined to provide details.

Meanwhile, sources close to Mahathir's camp told Malaysiakini yesterday that Kencana Capital Sdn Bhd, another venture capital firm owned by Mokhzani, was raided on Tuesday.

This cannot be independently confirmed with the company.

Malaysiakini has attempted to contact IRB regarding this matter and is currently awaiting their response.

In May, Mahathir had complained that IRB was targeting his associates.

Although he did not name anyone, businesses owned by two known Mahathir associates - Lee Kim Yew and Mustapha Kamal Abu Bakar - have been having trouble with the taxman of late.

Mahathir also alleged that donors to Pakatan Harapan were being unfairly targeted by the authorities.

The former premier's rivals claim that Mahathir's children benefitted from his position and are among the wealthiest people in Malaysia.

This was also an issue raised by the opposition in the past, prior to Mahathir crossing over the political divide.

Mahathir, on the other hand, denied this allegation.