A man accused of murdering a father and his two children in a deliberate blaze told his co-accused he wanted a pub to be burned down, a court has heard.

Scott Snowden was said to be "a bit fuming" after being barred from the Mariners pub in Helensburgh, Argyll, and told Robert Jennings: "You know what to do," jurors heard.

The High Court in Glasgow has heard how the Mariners was linked to Thomas Sharkey Snr who died following a fire at his home in 2011.

His children, Thomas Sharkey Jnr, 21, and eight-year-old Bridget, died in the fire at their home in Helensburgh on July 24 that year.

Snowden, 37, and Jennings, 50, deny murdering the three members of the family by pouring petrol, or something similar, through their letterbox and setting fire to it.

The court has already heard Mr Sharkey planned to renovate and run the Mariners pub but it was burnt down weeks before it was due to open.

Witness Lee McCarthy, 31, recalled being at Jennings' home days before the Mariners' fire on April 19, 2010.

During the visit Snowden arrived at the house. Asked how Snowden was, the witness said: "He was a bit fuming really ... He said that he was barred from Mariners."

The name of another man, Mr May, came up in the conversation before Snowden addressed Jennings, the witness said.

"He said to Mr Jennings, 'You know what to do'," the witness told the court. Asked to expand on that, Mr McCarthy replied: "(He) just basically said he wanted it burnt down."

Between them, Snowden and Jennings face 22 charges, all of which they deny, including an allegation of setting fire to the Mariners in 2010.

Both men have lodged special defences of incrimination and alibi, with Snowden claiming he was in Mexico when the fire at the Sharkey home was allegedly started, while Jennings claims he was home alone in Helensburgh. The trial continues.