Chirayu is also director of the Crown Property Bureau.

"Temasek has held about 4 per cent of Siam Commercial Bank for years after buying shares from Sanwa Bank. The Japanese bank wanted to sell the shares and we helped by finding it a potential buyer. Temasek emerged and has been a good partner for years," Chirayu said in an interview with the "Insight Thailand" radio show yesterday.

Thanks to the partnership, when Temasek was about to buy Shin Corp, it approached SCB as a co-investor. Chirayu said the bank agreed to Temasek's request for two reasons: Temasek had been a good partner and the transaction would help boost the bank's retail banking business.

Temasek does not appear on the list of SCB's major shareholders dated March 15 this year. However, the list does contain DBS Bank, which is directly owned by Temasek. DBS holds a 2.53-per-cent stake in SCB.

The Government of Singapore Investment Corp holds another 2.57 per cent through two separate accounts.

Chirayu insisted in the interview that he played no role in matching Temasek with MR Tongnoi Tongyai for the position of adviser to the company's Thai office. Temasek announced without elaborating on Thursday that Tongnoi would not be working for it. Tongnoi is a deputy principle private secretary of HRH Crown Prince Maha Vajiralongkorn.

Given Tongnoi's social position, there is speculation that Temasek wanted to appoint him to quash negative criticism of its investment in Thailand. Chirayu admitted that Tongnoi's rejection of Temasek's offer could spark suspicion.

"I didn't know that MR Tongnoi was approached. I found out when he turned down the invitation. This time, my name was implicated. I think this is a misunderstanding as I had no part in it," he said.

Temasek has said it is ready to follow the rules to show its commitment to investment in Thailand. The company's Bangkok office is being established to oversee its investment here.

A source at Temasek said the company had a long-term commitment to Thailand, where it sees high growth potential in the telecom industry and has invested in more than just voice services.

"There's a lot of opportunity here," said the source.

There are over 32 million mobile phone users in Thailand, representing around 50 per cent of the population.

It is predicted that number will increase to cover 80 per cent soon.

The Temasek source declined to comment on the ongoing investigation into the allegation that the Temasek-Shin Corp deal involved the use of a nominee.