Freetown - Sierra Leone's transport minister has been suspended following a weekend helicopter crash that killed 22 mostly Togolese sporting officials and fans, state radio said on Tuesday.

"The minister of transport and communication Prince Harding, the director and deputy director of civil aviation have been temporarily relieved of their duties pending investigations," said the radio.

Twenty-two of the 23 people on board a Russian-made Mi-8 Paramount Airlines helicopter, which caught fire Sunday and crash-landed on the runway while coming in to Sierra Leone's main Lungi airport, died in the incident.

Authorities in the small African country have launched an investigation into the crash and grounded all commercial helicopter services, a government statement said late on Monday.

"It is a pity the incident has happened. I am not worried about being minister but I am thinking about these people whose relatives have perished," Harding told AFP.

"However I feel saddened that after five years in a very difficult ministry which I have managed, and at the end of my term, this has happened," he said.

State radio also said Togo will dispatch an aircraft to collect the remains of its nationals on Wednesday.

The 20 Togolese, who include the country's sports minister Richard Attipoe, were football support staff and fans travelling with their national team.

Sierra Leone's information minister Septimus Kaikai vowed his government will "take a serious look at these commercial helicopter companies to make sure that the public is given adequate safety."

Denis Ivanov, chief of Paramount Airlines which is on the European Union blacklist of airlines which bars it from EU airspace, said a technical fault was unlikely to have been the cause of the accident.

Paramount Airlines, operates four blue, white and yellow helicopters which offer a seven-minute shuttle service between Freetown and the airport.

Alternative routes to the airport are either a 30-minute ferry ride or 110 kilometres by rough road.

Paramount's and other commercial helicopters plying the route in this poverty-stricken country were grounded in January for security checks and re-certification by authorities and resumed operations a month later.

Both Togo and Sierra Leone have declared three days of national mourning for the victims.