AceShowbiz -

Heidi Klum's slightly-over-a-year relationship with her bodyguard Martin Kirsten has fallen off the wagon. The supermodel is single again after splitting from Kirsten a few weeks ago, both personally and professionally.

Klum began dating Kirsten a few months after she filed for divorce from husband Seal. She stated that she never looked at another man while married to Seal after he said in a statement that she didn't wait to "fornicate with the help" before their separation was made legal.

In September 2012, Klum admitted to dating Kirsten who had been working for her for four years at that time. "I trust him with my children's life," the mother of four told Katie Couric. "He's a great man and recently we just got to know each other from a completely different side."

Regarding their separation, a friend close to Klum told People magazine, "Martin was there for her during a challenging time in her life and it was something she will always be grateful for." Another source also confirmed the end of their professional relationship. "They are no longer working together," the source told People, adding "Life is about timing. He was incredibly supportive and they were there for each other, but they're moving on now. They still have a great friendship."