Rights groups said the case highlighted how Thailand's broad defamation and computer crime laws impede investigative journalism.
Jonathan Head, the BBC's Southeast Asia correspondent, faced up to five years in jail after his report exposed how two foreign retirees had properties on Phuket island stolen from them by a network of criminals and corrupt officials.
Rights groups said the case highlighted how Thailand's broad defamation and computer crime laws impede investigative journalism and make it difficult to uncover wrongdoing in an endemically corrupt country.
The lawyer who brought the suit -- Pratuan Thanarak -- decided to drop the charges against Head on the first day of the trial on Wednesday.
"The plaintiff has withdrawn his case against BBC journalist Jonathan Head," the BBC said in a short statement.
Foreigners cannot own land in Thailand but they often get around the prohibition by putting assets in the name of Thais, or by setting up majority Thai-owned shell companies.
The 2015 BBC report detailed how a network of Phuket criminals, aided by corrupt officials, stole properties from foreigners by forging land title transfers or company ownership records.
One of the victims who featured in the report, British national Ian Rance, was named as a co-defendant in the defamation suit. Charges against him were dropped on Thursday.
Rance said he lost $1.2 million worth of properties after his then-wife and a gang of moneylenders forged property paperwork.
According to the report, Pratuan admitted on tape to certifying Rance's signature without him being present, a move which helped the wife transfer his properties out of his name.
She was later convicted and jailed for the scam.
But Rance has been hit by several legal cases since going public, a common outcome for whistleblowers in Thailand which markets itself as a dream retirement destination for wealthy foreigners.
"I am sad to reflect that many others, both Thai and foreign investors and business people, may be defrauded in a similar manner," Rance told AFP after his case was dropped.
He added that he had been left penniless by his unsuccessful attempts to recover his stolen properties through the Thai courts.
Unlike many countries where defamation is a matter for the civil courts, in Thailand it is a criminal offence.
Private citizens can also launch their own prosecutions and are not forced to pay costs if they lose.
Similar cases have been brought in recent years. Local news site Phuketwan closed down in 2015 after running out of money in its successful attempt to defeat a suit brought by Thailand's navy.
Andrew Drummond, a British crime reporter, left the country the same year because of multiple cases brought by those he exposed, as did British labour rights activist Andy Hall in 2016.