Russia has rejected European Union demands for an international investigation into the death of jailed opposition figure Alexei Navalny, as his mother made an emotional plea for the Kremlin to release his body. “I appeal to you Vladimir Putin, because the solution to this problem depends only on you,” Lyudmila Navalnaya told the Russian president in a one-minute video filmed outside the “Polar Wolf” prison camp where her son had been jailed while serving a decades-long sentence. Russian authorities said the 47-year-old suddenly died there on Friday while taking a walk. “Let me see my son. I de…