The manifest showed they were reclaimed lumber bought from an old-wood dealer in the northern province.
Soldiers from the 7th Infantry Division and forestry officials raided Mrs Monthathip's house in Wiang Ping Villa housing estate in Doi Saket district on Friday.
They had been tipped off by people in the areas there were a lot of logs and planks on plots owned by influential politicians including the Shinawatras, suggesting possible illegal logging and trade.
Mrs Monthathip was not at home during the raid but one of her employees showed the manifest and proof of possession of the wood.
On Thursday, teak logs and planks were found on the land owned by Yossanan Wongsawat, a former Chiang Mai MP and son of Somchai and Yaowapa, the brother-in-law and sister of Thaksin.
Suthep Pawaretvidhyararn, director of the Chiang Mai Forest Office, siezed all logs found on Mr Yossanan's land to determine whether they were reclaimed lumber and consistent with the manifests.