Pop singer Justin Timberlake is in mourning following the death of his beloved grandfather.

The SexyBack hitmaker's maternal grandpa, former firefighter Bill Bomar, passed away on 29 December (12) from heart trouble and dementia.

Timberlake and his new wife, actress Jessica Biel, jetted to the star's native Tennessee to pay their respects at the start of the New Year by attending his funeral at Mumford Chapel.

The singer's grandmother, Sadie, who was married to Bomar for 63 years, tells America's Star magazine, "I hate to tell you this, but my husband passed away on December 29. Justin was very upset. We all are, really. He and Jessica were here for the funeral on Jan. 2. He loved his grandfather very much."

Bomar has been sick for some time - he was unable to fly to Italy for his grandson's nuptials in October (12), because he was recovering from heart surgery.