Louis Tomlinson in mourning for step-grandmother

One Direction star Louis Tomlinson is in mourning after the death of his step-grandmother.

Margaret Tomlinson, the mother of the singer's step-father Mark, reportedly passed away last week (begs30Dec13).

Confirming the news on Twitter.com, Mark wrote, "The birds are singing today. Rest in Peace my beautiful Mom. I'm going to really miss you."

While Louis' step-grandfather added, "There was never one day in 47 years of being married to me that Mrs T didn't tell me she loved me."

Margaret and Keith Tomlinson became Louis' step-grandparents when their son Mark married the star's mother Johannah when the 22 year old was a toddler.