The Pathan people (also known as the Pasthun) is an ethnic group of around 50 million living scattered across the border between Pakistan and Afghanistan, and also Iran and India.
Wikipedia explains:
There are many conflicting theories about the origin of Pashtuns, some modern and others archaic, both among historians and the Pashtuns themselves. According to most historians and experts, the true origin of the Pashtuns is some what unclear.[
However, there is also a claim that they could be one of the lost tribes of Israel.
Experts at Mumbai's National Institute of Immunohaematology believe Pashtuns could be one of the ten "Lost Tribes of Israel".
Source Daily Telegraph
Until now the supposed link between Pathans and Jews has only been discussed on the fringes of the academic and anthropological worlds. But now Shahnaz Ali, an Indian researcher from the National Institute of Immunohaematology in Mumbai has received a grant from Israel to test the theory with DNA samples she collected from Pathans in India. She will conduct her research at the prestigious Technion Institute in Haifa.
Source ABC News
The purported Jewish origins of the Afridis is well documented in medieval texts. "The tribe was driven into exile and eventually into oblivion by the Assyrians in 721 BC. Great Jewish writers like the 10th century Saadia Ga'on and the 11th century Moses ibn Ezra mention Afghanistan and the Pathan territories in Pakistan as the home of Jews descending from the Lost Tribes," Aafreedi says. "And the second President of Israel, Itzhak Ben-Zvi, a Lost Tribes enthusiast, wrote in great detail about the Israelite descent of the Afridi Pathans in his book The Exiled and the Redeemed in 1957."
Source: Blog about Dr. Navras Jaat Aafreedi research
Note: Afridi is a tribe among pathans and they are linked to Ephraim tribe.
This video also claims that Pathan are actually Jews.
Some claim that Pathans are the lost tribes of Israelites, e.g. this book and this documentary.
Some claim that Pathans have similar customs to Jews.