The true death toll from the Ebola epidemic is being masked by chaotic data collection and people’s reluctance to admit that their loved ones had the virus, according to one of west Africa’s most celebrated film-makers.

Sorious Samura, who has just returned from making a documentary on the crisis in Liberia, said it is very clear on the ground that the true number of dead is far higher than the official figures being reported by the World Health Organisation.

Liberia accounts for more than half of all the official Ebola deaths, with a total of 2,458. Overall, the number of dead across Liberia, Sierra Leone and Guinea has exceeded 4,500.

Samura, a television journalist originally from Sierra Leone, said the Liberian authorities appeared to be deliberately downplaying the true number of cases, for fear of increasing alarm in the west African country.

“People are dying in greater numbers than we know, according to MSF [Médecins sans Frontières] and WHO officials. Certain departments are refusing to give them the figures – because the lower it is, the more peace of mind they can give people. The truth is that it is still not under control.”

WHO has admitted that problems with data-gathering make it hard to track the evolution of the epidemic, with the number of cases in the capital, Monrovia, going under-reported. Efforts to count freshly dug graves had been abandoned.

Local culture is also distorting the figures. Traditional burial rites involve relatives touching the body – a practice that can spread Ebola – so the Liberian government has ruled that Ebola victims must be cremated.

“They don’t like this burning of bodies,” said Samura, whose film Living with Ebola premieres on 12 November on Al Jazeera English. “Before the government gets there they will have buried their loved ones and broken all the rules.”

Kim West of MSF admitted that calculating deaths was “virtually impossible”, adding that only when retrospective surveys were conducted would the true figure be known.

Samura believes sexual promiscuity among westerners could play a role in the virus’s spread abroad. Almost immediately after the outbreak was reported in March, Liberia’s health minister warned people to stop having sex because the virus was spread via bodily fluids as well as kissing.“I saw westerners in nightclubs, on beaches, guys picking up prostitutes,” he said. “Westerners who ought to know better are going to nightclubs and partying and dancing. It beggars belief.It’s scary.”

He said another striking feature was that the ineffectiveness of years of aid had been laid bare: “Money has poured in from the west, but it has gone to waste. Ebola should make us think about how the west gives aid to Africa; aid has not been used to create a system able to cope with this challenge. Ebola has exposed the fact it is not working. That money has gone to waste.”

A committee of MPs recently criticised the Department for International Development and the EU for failing to address the problem of aid being misappropriated. It said just £2.4m of £37m of aid had actually made its way to Liberia’s health ministry.