London: The father and half-sister of Meghan Markle, the Duchess of Sussex, have launched fresh tirades against Britain's royal family over an alleged silent treatment ever since the former actress got married to Prince Harry.

Thomas Markle, who celebrated his 74th birthday today, said he would continue to speak to the media until the royal family breaks its silence.

I was silent for a full year and the press beat me up every day saying I was a hermit hiding in Mexico, so I gave my story, he said.

"Apparently that interview put the royal family in their silence mode... so, I gave another interview to break the silence. All they have to do is speak to me, he said.

In an interview with celebrity news website TMZ', he also indicated his amusement at the effect he had on the British royal family.

I'm enjoying the fact that I can make the entire royal family not speak and maybe I can get a laugh out of the Duchess," he said.

Markle, a former Hollywood lighting director, has given numerous interviews in recent months, including a paid interview with the Sun' newspaper in which he revealed his former actress daughter hadn't returned his calls for over two months.

He has been at the centre of media controversies ever since he was caught up in a staged-photography row days before the wedding. It resulted in him not attending the wedding to walk his daughter down the aisle at Windsor Castle on May 19, something he later said he cried over.

In his latest interview, he expressed fears over Meghan's well-being as the newest member of the royal family in Britain.

I see it in her eyes. I see it in her face and I see it in her smile. I've seen her smile for years. I know her smile. I don't like the one I'm seeing now. This one isn't even a stage smile this is a pained smile," he said, claiming that the 36-year-old actress-turned-royal was struggling under the pressures of her new role.

"It really worries me. I think she's under too much pressure. There's a high price to pay to be married to that family," he said, adding that he wanted to a part of her life and as grandfather to any future child that is born to her and Harry.

I'd like to put our differences behind us, and get together. I miss you very much," he said.

His latest tirade came as Meghan's half-sister, Samantha Markle, also launched into a fresh attack on the royal family, branding it an embarrassment for ignoring her father.

"Glad you have so much time to gallivant around paying tribute to others while ignoring your own father, she tweeted as Prince Harry and Meghan attended a special tribute event to mark the 100th birth anniversary of anti-apartheid leader Nelson Mandela in London on Tuesday.

"Act like a humanitarian, act like a woman! If our father dies I'm holding you responsible, Meg," she said, in an apparent reference to Thomas Markle's heart procedure in the days before the royal wedding in May.

"My father is not an embarrassment for loving his daughter! The royals are an embarrassment for being so cold. You should be ashamed of yourselves," she added.

Meghan, as Duchess of Sussex, has had a packed schedule of royal duties since her wedding, including a tour of Ireland with Prince Harry as well as her first official outing with the Queen. Over the weekend, she was pictured laughing and chatting animatedly with her sister-in-law, Kate Middleton the Duchess of Cambridge in the royal box at the Wimbledon championships.