My latest project has been the making of Planet Ustinov, a TV film in which Sir Peter Ustinov travels along the same route as Mark Twain did in his book, Following the Equator.

The most ludicrous country we went to was Kiribati, in the Pacific. On entering the country, all of us, Sir Peter included, got stamps in our passports saying "Misbehave prohibited". Kiribati is actually pronounced Kiribas. They write "s" as "ti" because the first missionary there lost the "s" from his printing machine.

The population is 80,000 but the country spans a greater distance from east to west than the USA. When the President of Kiribati (his name is Tito, pronounced Sito) travels from one side of his country to the other, he needs to fly via two foreign countries.

We stayed on a tiny island called Aranuka, right by the equator. There was no hotel, only a laughably named "government resthouse" without electricity. Sir Peter sat on the verandah overlooking a lagoon, musing calmly on the purposelessness of progress. But the next morning - after what he described as the worst night's sleep of his life - I heard him blaming the mosquitoes on Mark Twain.

One passport mishap on the trip was having three of our team - including Sir Peter - refused visas to enter the USA, with no reason given. In fact it was a trivial problem regarding work permits, but being a VIP gives you no special treatment.

Having Sir Peter's passport impounded at Durban airport was a similar case. We arrived late at night without onward tickets. The officials said "Sorry, rules are rules", and refused us entry. They let Sir Peter sit in the VIP lounge on condition that he give up his passport. I suppose they thought we were backpackers planning to become a drain on the state.

Michael Waldman's four-part series 'Planet Ustinov' starts on Channel 4 on 23 November.