A Nigerian MP, who requested to remain anonymous, told the BBC that the senate was unable to start considering the proposed 2016 budget because hundreds of copies of the document in question had gone missing.
The delay could worsen the country's economic crisis as it deals with the impact of plunging oil prices.
President Muhammadu Buhari delivered the hard copies of his first budget to both houses at the end of last month.
It detailed his plans to raise spending by 20% by borrowing heavily amid falling global oil prices.
The president, who came to power last May, also pledged to invest in agriculture to create more jobs.
BBC Nigeria analyst Naziru Mikailu says this is an embarrassing development for the country's parliament and the government in general.
Both houses are expected to take about two months to consider the $31bn (£20.8bn) budget.
Source: bbc.com
