SINGAPORE - He had information that a crime was being committed.
So, in 2011, Mr Tan Keng Hong reported it to the authorities, and the culprits were eventually taken to task.
But soon after the court case ended in January 2012, the 52-year-old said he and his family became victims of incessant harassment, which has continued to this day.
This, he alleged, was because his name, identity card number and address were included in an open-court document used in the case.
Now, Mr Tan has filed a law suit against the Maritime and Port Authority Of Singapore (MPA), which carried out the prosecution, seeking damages for the grief he and his family have been through.
In his statement of claim filed in July, Mr Tan detailed more than seven instances where he and his family had been harassed at their first-storey unit.
On one occasion, someone had used a bicycle chain to lock his metal gate. Some of his flowerpots were smashed and paint was splashed on his door and windows on several occasions. He also received incessant calls on his phone in the middle of the night, with the caller making threats and cursing him.
As a result, he and his family are now "living in constant fear, stress, anxiety", said the court document.
Before this, he and his family had resided "without incident" at the three-room flat since 2010, he said.
Mr Tan, who is married with a 23-year-old son, said they are still living there as they have no money to move.
He has since made 12 police reports on the harassments.
He said he installed a closed-circuit television camera outside his unit, but removed it earlier this year during a block upgrading.
Mr Tan, who worked as a marine coordinator for another shipping company when he made the report, had provided information that led to the prosecution of a Singaporean company known as Elcarim Petroleum.
In August 2011, he witnessed the company's motor tanker loading a cargo of unrecovered waste oil, which they were not supposed to, at Tanjong Kling Road.
In January 2012, the company pleaded guilty to five charges of contravening Regulation 7 of the MPA (Dangerous Goods, Petroleum and Explosives) Regulations.
It was fined $7,500.
In his statement of claim, Mr Tan, through his lawyer M. Lukshumayeh, said there was an "implied agreement" that MPA should protect him by not disclosing his identity and address.
Mr Tan left his old job and was subsequently jailed for 11 months for smuggling contraband cigarettes across the Causeway.
Since his release from jail in February, he has been working as a freelance marine coordinator.