Half-sister Samantha Markle said the bride-to-be needed to “step up to the plate and make sure he is well taken care of” as she gets ready to marry Prince Harry in May.

Their father Thomas Markle was "declared bankrupt in 2016" and is now living in Mexico.

In an interview set to be aired tonight, Samantha told Australian website 9 News she contacted Meghan on behalf of their dad, seeking financial assistance, but was left disappointed.

She said: “Honestly – what she could spend in a weekend would greatly help dad, so that should be a priority.

“I think you need to step up to the plate and make sure he is well taken care of.”

She referred to Meghan dress in the couple’s official engagement photos.

She said: “If you can afford $75,000 (£42,500) for a dress, you can afford $75,000 to help your dad. That’s how I feel, that’s who I am.”

Samantha, who lives in the small town of Ocala in Florida, US, said she would help her father “in a heartbeat” if she had the money.

She has debilitating multiple sclerosis and has been wheelchair-bound for more than 10 years.

Samantha has masters degrees in counselling, vocational rehabilitation counselling and creative writing, as well as bachelors degrees in criminology and psychology.

Meghan and her half-sister both grew up on the sets of Hollywood sitcoms and soaps.

Their father was a Daytime Emmy Award winning lighting director who worked on famous sitcoms and soaps, including Married with Children and General Hospital.

Samantha said she hasn’t spoken to Meghan in three years.

She added: “The last words I heard from her were ‘I love you babe, it was so great catching up and talking’. She said ‘let’s keep in touch’.”

Daily Star Online contacted the Kensington Palace and a spokeswoman said they did not have a comment.