Cambodia's decision to revoke the diplomatic passports of non-citizens demonstrates the strong ties between Cambodia and Thailand, Foreign Minister Don Pramudwinai said Tuesday.

The move follows a report that fugitive former prime minister Yingluck Shinawatra benefited from this privilege.

It is a "clear, official indication" of the Cambodian government's stance that shows "we care for each other's feelings", Mr Don said after learning of Phnom Penh's move.

Last week, Cambodian Prime Minister Hun Sen issued instructions telling officials to annul diplomatic passports given to non-Cambodians who work as advisers and assistants to authorities, and to reject any new passport applications, The Phnom Penh Post reported on Monday.

Kin Phea, director-general of Cambodia's International Relations Institute at the Royal Academy of Cambodia told the paper the instructions "may be linked to reports about Yingluck or other cases involving diplomatic passports", though Cambodian Ministry of Foreign Affairs spokesman Ket Sophann did not make a direct reference to Yingluck.

Last week, Hong Kong's South China Morning Post reported that Yingluck used a Cambodian passport to register as director of PT Corporation about a year after she left Thailand in August of 2017. The former prime minister fled before a court found her guilty of negligence in the corruption-plagued rice-pledging scheme. She was sentenced to five years in jail.

The youngest sister of former prime minister Thaksin, also living in self-exile to escape a two-year jail term handed down by the Supreme Court in 2008 for abuse of power, may have travelled to Cambodia where she reportedly travelled to Dubai and the United Kingdom. Cambodian officials say they did not allow Yingluck to escape through their country and said she had never been issued with a Cambodian passport.

Hun Sen only said in his order the revocation of diplomatic passports is only aimed to "prevent such passports from being used incorrectly", according to The Phnom Penh Post.

Despite the belief that his instructions may be linked to the Yingluck case, Kin Phea told the paper "no action would be necessary if Thailand had not requested cooperation in the Yingluck case".

"There is no need for an investigation if it doesn't harm relations between Cambodia and Thailand," the paper quoted him as saying.

"Cambodia is our friend. We have to work together on various issues in the future," the Thai foreign minister said.