Ousted former Thai Prime Minister Thaksin Shinawatra arrived in Phnom Penh Tuesday morning to take up his new job as the adviser of Cambodian Prime Minister Hun Sen and the Royal Government.

Thaksin will give a lecture on economic issues to about 300 Cambodian business leaders at the Ministry of Economy and Financeat at the invitation of Prime Minister Hun Sen.

"Cambodia welcome the arrival of Thaksin Shinawatra," said Phay Siphan, spokesman of Council of Ministers at a press conference held at the Council of Ministers on Tuesday morning, adding that "Cambodian leaders will have a banquet to welcome Thaksin."

Thaksin arrived at Cambodia's military airport about 9:00 a.m. local time by a private plane. There was tight security for Thaksin's arrival and the reporters were banned to come near or close to the spot.

Hun Sen told reporters on Sunday that Thaksin will arrive in Cambodia to give an economic lecture on Thursday. He said that "Thaksin will make a lecture on economic topics in Phnom Penh on Nov. 12 in the morning to 300 people. I cannot tell you when and from where he will come through, but he will make a lecture here."

Relations between Thailand and Cambodia were strained in the past week when Cambodia named Thaksin as its economic adviser. Thailand recalled its ambassador Thursday, and Cambodia followed suit.

Thaksin was ousted in a 2006 military coup for alleged massive corruption and other charges. His supporters say he should be pardoned and returned to power. Since the coup, Thaksin has lived abroad to escape a corruption conviction and two-year prison sentence.

Thaksin, born in Thailand's northern province Chiang Mai in 1949, became one of the richest people in Thailand by setting up telecommunications companies like Shin Corporation and Advanced Info Service before entering politics.

Thaksin entered politics by joining the Phalang Dharma Party ( Power of Justice Party) in 1994, and once served as deputy prime minister and foreign minister in two administrations.

"Thaksin can stay in Cambodia as a guest of Cambodia. He can also be my adviser on the economy," Hun Sen said as he arrived in the beach resort of Hua Hin for the Association of Southeast Asian Nations (ASEAN) summit last month. The Cambodian leader repeated an earlier invitation to Thaksin to stay in Cambodia and rejected Thai claims that Phnom Penh would have to extradite the tycoon.

"Our concern is for humanitarian reasons, it is friends helping friends. The internal affairs of Thailand would be left for Thai people to resolve, I am not interfering," Hun Sen said earlier.