Creative agency Leo Burnett Malaysia issued a letter of demand to filmmaker Tan Chui Mui and the production house Da Huang Pictures.

This is over Tan's claim that the agency plagiarised her team's work for the Petronas-commissioned TV commercial 'Rubber Boy'.

The agency said the letter is to give Tan and the firm a chance to retract "unfounded" statements on social media over the matter.

"Leo Burnett reiterates that key elements including the message, the characters, the setting in the rubber estate and the emotions, are very much a part of the agency's script, which was shared with three directors in 2014, including (directors from) Da Huang.

"Neither Tan nor Da Huang Pictures furnished those kept elements.

"There appears to be an intention to cause damage to Leo Burnett's reputation and that of its clients through these social media postings, which were shared and later picked up by mainstream media," the agency said in a statement.

Leo Burnett said it had already explained to the Da Huang Pictures team that 'Rubber Boy' has a "different storyline" from the concept pitched by the team in 2014.

The agency's creative director James Yap earlier said 'Rubber Boy' is in fact based on his "family story".

Tan in various Facebook postings under the hashtag #LeoBurnettplagiarism said her team had pitched a story about a rubber tapper's son to the agency in 2014, after she was approached by the agency to develop a concept for a Chinese New Year commercial.

She said the story the team had pitched was based on her friend's childhood memory of the moment he realised how much his rubber tapper mother sacrificed to raise him.

Her friend realised this when as a teenager he tried and failed to lift the buckets his mother carried every day to tap rubber. Seeing him struggle, his mother lifted the bucket wordlessly and walked away, leaving her son in tears, she said.

The pitch by Da Huang included location recce and potential casts, she said, but in January 2015, Leo Burnett told them their idea was not selected.

The 'Rubber Boy' commercial by Leo Burnett, which tells the tale of a boy and his rubber tapper mother, was released on online in February 2016.

It features a scene where the boy tries and fails to lift a bucket filled with tapped rubber, and his mother carries it away without a word. He then realises his mother's hard work.

The Da Huang team then met Leo Burnett representatives, who informed them they cannot take legal action as ideas are not protected under Malaysian copyright law, she said.

The team was also told 'Rubber Boy' only included two scenes originating from Da Huang's script, she said.