BANGKOK, April 3 (Xinhua) -- Thailand's Prime Minister Surayud Chulanont said on Tuesday that investigations over charges against ousted premier Thaksin Shinawatra might be wrapped up by the end of April.

    "I can say that we are closing in on the final chapter of Mr. Thaksin's future," Gen. Surayud was quoted by Bangkok Post's web news as saying during his visit to Tokyo.

    He said that Thaksin was free to come back to Thailand but his return might prove difficult.

    "Yes, as a Thai citizen he can come back to Thailand, but again as one who caused big trouble in Thailand, I think it is not easy for him to come back," he told a news conference in Tokyo on Tuesday.

    Thaksin, who was ousted by a military coup last September, faces five lese majeste charges. He is also accused of corruption during his five years in office.

    Gen Surayud is on a four-day visit to Japan, and was to sign a free trade agreement between Thailand and Japan later on Tuesday.