Britain said Thursday it has sent a letter to Secretary-General Ban Ki-moon with new information on three further incidents of alleged chemical weapons use by the Syrian government, AP reported. Britain's U.N. Ambassador Mark Lyall Grant said his government has continued to provide new information to the secretary-general and the head of the U.N. team Ban appointed to investigate alleged chemical weapons attacks in Syria. Ban is insisting on a broader investigation, including a December incident in Homs raised by Britain and France. He appointed Swedish chemical weapons expert Ake Sellstrom to lead a U.N. investigation. Syria has refused to allow his team into the country. "We continue to inform the secretary-general and Mr. Sellstrom of any information as and when we get it," Lyall Grant told several reporters. "I sent a further notification to the secretary-general last week." The U.K. Foreign Office said the letter was meant to draw Ban's attention to three further allegations of chemical weapons use and ask that those be included in the U.N.'s investigation. Those allegations relate to incidents which reportedly took place in March and April of this year and which have been reported in the media, the Foreign Office added. "The U.K. is extremely concerned about the ongoing allegations of chemical weapons use in Syria," it said in a statement. The confirmed use of chemical weapons could escalate the international response to the more than two-year-old conflict, which has killed more than 80,000 people, according to the United Nations.