The US Secret Service has confirmed that the White House has received an envelope containing the poison cyanide. Although initial biological testing did not detect any traces of the poison, additional testing was carried out, with the results confirming that the envelope had been tested positive for containing cyanide.
The envelope was received on the 15th of March, and is currently being sent to another facility for further testing, with the Secret Service confirming that they will continue to investigate into the incident. Luckily, there are no concerns of damaging exposure for the employees who will be carrying out the additional tests in the screening facility.
Rather than being sent anonymously, a return address was written on the envelope. This address belonged to a man who had previously sent in other letters. The last one to be received from that address was in 2012, and the package contained mini alcoholic drinks. Prior to this, the White House has received envelopes and packages from the same man that contained faeces and urine.
In 2013, the poison ricin was found in letters that had been sent to Mr Obama, Senator Roger Wicker, and Sadie Holland, a Mississippi judge. The letters addressed to the president and the senator were intercepted before they reached their recipients, but the one to Judge Holland was not intercepted. Luckily, Ms Holland was unharmed by the poison.