Thai police have recommended that former PM Thaksin Shinawatra is charged on three counts of insulting the king.
Mr Thaksin was ousted in a coup on 19 September
Police chief Sereepisut Taemeeyaves said he was also investigating several possible lese majeste cases, including a recent TV interview of Mr Thaksin.
The former Thai leader was ousted in a military coup last September.
The general who led the coup, Sonthi Boonyaratglin, has confirmed that the authorities still plan to hold elections by the end of this year.
In a nationally televised press conference on Tuesday, to mark the six-month anniversary of the takeover, he said: "We will have free and fair elections on schedule."
The military has long promised to draft a new constitution, hold a referendum on the document and then hold general elections before the end of the year.
But critics have voiced doubts about whether all this is possible in the timescale.
The military junta and its government, led by Prime Minister Surayud Chulanont, have also been criticised for not finding more definite evidence to prosecute Mr Thaksin over alleged corruption - one of the main reasons given for the coup.
"I am fully aware that people are waiting for the prosecution of wrongdoers, but we have to be fair to all parties," Mr Sonthi told reporters on Tuesday.
These latest allegations of lese majeste, which police have recommended are taken up by prosecutors, relate to alleged offensive remarks about the country's revered King Bhumibol Adulyadej.
They stem from comments Mr Thaksin is said to have made to a group of taxi drivers, his weekly national radio address, and an incident when his supporters waved "Long Live the King" flags during his visit.
The three charges that have already been recommended to prosecutors could theoretically put him in jail for 45 years, police have said.
Another three cases are also being reportedly looked into - including a TV interview of Mr Thaksin on CNN earlier this year.
"The prosecutors want us to provide them with more evidence on some of the cases before they decide whether to charge Thaksin in court," police chief Sereepisut told Reuters news agency.