SpaceX owner Elon Musk said Monday in a statement that last month's explosion of SpaceX's Falcon 9 rocket was caused due to a failed support piece, or strut. The failed strut allowed the helium bottle to burst freely inside the rocket's liquid oxygen tank, he said.

Musk during a conference call discussing the June 28 blast of its Falcon 9 rocket what was supposed to be a routine cargo mission to the International Space Station (ISS) told reporters that the helium bottle would have shot to the top of the tank with quite a high speed.

He mentioned that the findings presented by the company are the preliminary results of a weeklong investigation by the California-based company.

A NASA spokesman told Congress earlier this month the explosion of the rocket caused the American space agency loss of $110 million in equipments that were meant for astronauts living in orbit aboard the ISS.

The Southern California-based company said in a statement that several hundred struts fly on every Falcon 9 vehicle, with a cumulative flight history of several thousand.

"The strut they believe failed was designed and certified to handle 10,000 lbs (4,500 kilograms) of force, but failed at 2,000 lbs, a five-fold difference. Detailed close-out photos of stage construction show no visible flaws or damage of any kind", it said.

The strut which SpaceX said are responsible for falcon 9's explosion are each two feet (60 centimeters) long and an inch thick, and were furnished to SpaceX by an outside supplier.

Musk said SpaceX would return to flight with the Falcon 9 not before September. He also affirmed that they are not going to use these particular struts in the future and the company is further planning to start individual testing of each of its strut for future launches.