After being sent to the office of Mohammad Yasin, the Commons was told the package may be connected to anti-Muslim letters.
A suspicious package in Parliament has been linked to letters inciting a “Punish a Muslim day”.
Two people were taken to hospital as a precaution on Monday as police assessed a package, later found to be non-hazardous, at one of Parliament’s buildings.
Sent to the office of Labour MP Mohammad Yasin in the Norman Shaw Buildings, the incident prompted a response from specialist police officers and paramedics.
“Everyone is fine, but it was clearly a worrying incident,” a member of Mr Yasin’s staff said.
Speaking in the House of Commons after hearing news of the incident, Tory MP Michael Fabricant raised fears the package sent to Mr Yasin may be connected to reports anti-Muslim letters have been posted across the country.
West Yorkshire Police have confirmed they have received reports of “potentially malicious communications”, which are now being investigated by counter-terror police.
Social media users in London and Birmingham have also reported receiving the letters.
As MPs debated reports of the letters, Mr Fabricant – referring to Mr Yasin – said: “Earlier today, there was an incident in Norman Shaw North that involved him and his staff which may or may not be connected – but we think it might be – with this letter.
“We must pull together to ensure that this does not happen, not only here but throughout the country.”
Labour MP Yasmin Qureshi had earlier described the content of the letters, calling for an attack on Muslims on 3 April, telling MPs they offer attackers rewards “ranging from 10 points for verbal abuse, 50 points for throwing acid and 1,000 points for bombing a mosque to 2,500 points for nuking Mecca”.
In response to Ms Qureshi’s urgent question on the letters, Home Office minister Victoria Atkins told MPs the Government “condemns the content of the letters as clearly abhorrent, with no place in decent society”.
The debate also saw Conservative MP Anna Soubry call for a “proper legal definition of Islamophobia”.
Ms Atkins replied: “We do not accept the need for a definitive definition, but we know that Islamophobia is clearly recognised and that we have very effective monitoring of race-hate crimes.”
In response to the package sent to Mr Yasin’s office, a parliamentary spokesman said: “Today a suspicious substance was investigated by the Metropolitan Police and was found not to be hazardous.
“The affected area was temporarily cordoned off but no evacuation was necessary. Two people attended hospital as a precaution.”
A Metropolitan Police spokesman said: “Police were called at 12:58hrs on Monday, 12 March to reports of a suspicious package at Norman Shaw Buildings, Victoria Embankment, Westminster.
“Specialist officers are in attendance and the package is being assessed. A man and woman have now been taken to hospital as a precaution.”