Foreign Affairs Minister Anifah Aman has rubbished claims that the Malaysian government is responsible for influencing Japan to bar Opposition Leader Anwar Ibrahim from entering the country.

"It's unthinkable... the idea that I might have any influence over what the Japanese government does," he was quoted as saying in the New Straits Times.

Instead, Anifah (right) said the Japanese government had within its power, under the Immigration Control and Refugee Recognition Act, to deny "undesirable" individuals from the country.

"The Japanese government can deny entry to anyone who they find undesirable, and they are under no obligation to explain to us further why they have decided to do so," he was quoted as saying.

Such persons include those who have been convicted and imprisoned for any crime in Japan or elsewhere, he added.

Anwar, who yesterday landed at Narita Airport, Tokyo, was informed by Japanese immigration officers to take the first flight back home or “face deportation”, supposedly due to his 1999 conviction.

Anwar had previously been to Japan in 2006, 2009 and 2012 without obstacle. This time, he was to present a paper at the Nippon Foundation.

It was alleged when this was pointed out, Japanese officers then stated the refusal of entry was due to a “latest report" received, leading to speculation that “diplomatic pressure” had been exerted by the Malaysian government upon its Japanese counterpart.